The air was cold, and snow had just started to fall. Castiel thought that he should have bundled his vessel up, because a human would have been cold, but he couldn't care about looking normal right now. He was watching with an unfamiliar growing ache in his chest as his friend brushed off the big blue box that sat by the biggest tree in the neighborhood. The Doctor retrieved a key from behind his ear and smiled to himself. He loved seeing the inside of his TARDIS after a while of not letting his eyes take her in. He set the key in the lock and turned it, the click of the tumblers making him excited. He pulled the key out after, and turned to the other man, his smile fading.

"Come on, mate, it won't be that bad." He said, walking up to him, looking into those crystal blue eyes, holding more emotion than he'd ever seen. He didn't like the emotion he saw.

"You're leaving. And you're not allowing me to go with you. It is bad." Castiel told him, glancing to the TARDIS, knowing he'd never step foot inside it again. He wasn't sure he'd be able to find the Doctor on other worlds, and it would be impossible if he regenerated and had no idea what he looked like.

The angel took a few moments to map out the alien's eleventh face. The eyes of a young man, that have seen more than his fair share of tragedy, dark green and wise. His face was thin and his skin was perfect, not a blemish found along the pale expanse. His lips looked soft, but he knew they could be fierce with the way he formed words, and his chin and jawline were something the Time Lord didn't favor about himself. Castiel thought he was perfect. His hair was a rich brown, flop here and pushed back piece here. Flakes of snow were catching in it, and the soft wind blew the fringe into his eyes. How could someone look so young and so old at the same time? Only the Doctor could do it.

"Time was rewritten the moment I met you, and sometimes I have to get it back on track. I have things to do, Castiel." He informed, frowning now, taking in the appearance of the angel-the first real angel he'd ever met-and hating how upset he seemed. These times were always hard, and they broke something inside him each time he had to say goodbye. But it hurt so much more with him. He reached his hand forward and fixed the dark blue tie that fitted loosely around his neck, readjusting the collar after.

"I don't understand why I can't help you with those things. Have I not been helpful these past few months?" He asked, voice wavering just the tiniest bit. He kept his eyes down on the hands on his trench coat, long fingers slowly doing the buttons, slower than he honestly should have been, like he wanted it to last. Cas didn't have any objections to that.

The Doctor looked up at him with a look of awe and pain. How could he think that he wasn't helpful? He saw the hurt etched across the vessel's face, but could see through the skin and bone, into the pure angel within, "You don't think you helped me? Castiel, you saved me from monsters. You saved me from loneliness. You have been the most delightful companion I have ever had. I wish I didn't have to leave you behind."

The angel looked up at him, then. He saw that was the truth, and it was sparkling in the Time Lord's eyes, but then Castiel saw something that made him feel worse pain than being ripped from his vessel and sent back to Heaven; those beautiful green eyes were starting to water up. Cas reached a hand out and moved the fallen hair out of his face, tucking it behind his ear like he'd seen him do before. There was a hand cupping his cheek, and the younger looking man pulled him forward slightly, settling their foreheads together. The tears fell, rolling down the Doctor's cheeks, and his voice was a whisper.

"I wish I didn't have to leave you behind."

There was silence while he tried to compose himself. This had never been so hard. He felt like he was being ripped apart inside, and his heart was screaming for him to take Castiel onto the TARDIS, but his mind told him he mustn't. He couldn't. He took a deep breath and squeezed his eyes shut, taking in this last moment before he was moving away, letting him go, each step back to the TARDIS making him feel more and more lonely.

"I don't want you to leave. Please, don't go." Cas' voice sounded more rough than usual, like he was holding back tears even though he'd never shed one before, his vessel's heart booming in his ears. He'd never felt anything like this before.

"I'm sorry, Cas. It must be this way." He tilted his head to the side, but didn't turn around, he wouldn't let himself for the moment. The intake of breath Castiel took was uneven.

"If you need me... I will come whenever you call." He kept his eyes on the back of the tweed jacket, hands shaking slightly like he wanted to touch it; to turn the Time Lord back to him.

"I won't be calling you, Castiel." The Doctor said, and the truth hurt his throat as he said it, "It would not be wise. But I will be looking after you, I will never truly leave you... All you have to do is look hard enough into the stars."

The man in the trench coat almost let out a wry laugh, but it only came out as a grunt. He shook his head, "It seems silly, an angel looking up," He sighed, "for someone who most likely won't be there."

That cut deep. Castiel thinking he would actually not be there for him was unacceptable. He turned quickly and stomped his way back up to him, taking his face in his hands, looking into his eyes. His voice came out as a broken whisper, "I promise you; I'll be there. I promise, Cas. Please, trust me."

The angel tried to control himself, he really did. And he partly succeeded. He bit back a sob that was threatening to rack through him, and tried to wipe his face of all emotion. But he couldn't help when he pressed himself forward, the Doctor's lips less than an inch from his. The Time Lord stopped breathing.

"I love you, Doctor. I will forever trust you without doubt or hesitation." He whispered, the younger looking man feeling the breath ghost across his lips, and he wished so bad that he could just kiss him. But he wouldn't have left. He let out the breath he was holding, and his thumb rubbed across the stubble on the angel's jaw.

"Thank you, Cas," Then he was walking back to the TARDIS, for real this time, no going back. He ran his hand along the painted blue wood and smiled to himself before he opened the door. He mumbled, knowing the other man couldn't hear him, "You saved me from the monsters inside me, Castiel. And I am forever grateful. This time machine will always be home for you." And he stepped inside, closing the door behind him.

Castiel watched as the box came to life, listening for the last time to the whirring, sputtering, and all the other noises as the Doctor left the brakes on her. He walked up to the time machine and set his hand against it, shutting his eyes and feeling the end of his adventures fly away, until his hand was against air and he felt empty. He remembered the date; November twenty-fourth. He would never forget it. He knew going back to Heaven would make him into a soldier again, and he would have the happiness the Doctor gave him ripped out and forgotten, but he now had no other choice.

"Cas? Cas, are you listening? You're gonna get hurt if you're not listening to what's gonna go down." Dean shook him by a hand on his shoulder, wanting him to listen carefully so no harm would come to him. It was a late night in Wisconsin and they were getting ready to go into an abandoned warehouse where a group of demons were hiding out. Everything was set, and Castiel had volunteered to be the distraction so the brothers wouldn't be hurt.

He nodded, "I'm listening."

As they walked to the structure, snow started to fall. Castiel looked up to the sky, and through the patches of clouds he saw the stars. They were twinkling and shining bright, but one caught his eye. It was blinking, like a beacon. He focused his vessel's eyes just right and saw that it wasn't a star, but the blinking light of a blue police box. The feelings that ran through him were an unyielding rush. He felt home, more home than anything, even though he'd come to love the Winchesters. The Doctor was a repressed love, and the beautiful type forty TARDIS was his home. He was smiling and he knew it, cheeks tinted pink and looking completely unlike himself over the years after the Time Lord had left him. He'd been stripped of emotions and thinking for himself, then relearned them halfway with Sam, Dean and Bobby, and now he remembered everything. He felt free.

"Cas?" Sam looked at him. He'd stopped walking, so they all had stopped walking, "Are you okay? What are the angels saying?"

The angel felt complete bliss, and shook his head softly, "What's the date, Sam?"

"...November twenty-fifth."

"He's late." He smiled, watching the TARDIS descend closer and closer to the Earth, reaching into his pocket and taking out the old key that had been slipped into his pocket all those years ago without his knowing. It was about time he got to use it.